The present invention relates to a stereoscopic video system and in particular to an improved apparatus for delivering the stereoscopic video image directly to the eyes of the viewer.
In stereoscopic video systems, the purpose is to present images to the eyes of a viewer which will give the viewer the impression of actually seeing the real object by creating a three-dimensional image thereof in the viewer's brain.
Many prior art systems are known which effect this result, such as anaglyphic and vectographic systems, orthoscopic image tubes and holographic displays such as shown in U.S. Pat. Nos. 3,473,872 and 3,878,329. In each of these systems, the images are viewed by the eyes of the viewer through an intermediate space which permits the viewer to have a peripheral visual awareness of his surrounding or visual setting, which is in most cases irrelevant to the image being viewed, and therefore amounting to what can best be described as "video noise".
Moreover, the known prior art systems utilize rigid optics, moving mechanical parts or other devices and require that the viewer's head remain in precise alignment with respect to the image being brought to the viewer's eyes.
Examples of these types of prior art systems are those disclosed in U.S. Pat. Nos. 3,860,752 and 3,525,807 wherein the apparent position of the image remains unaffected by small movements of the head; however, the brightness of the image is diminished and the image vanishes altogether with a significant rotation. These types of systems are extremely complicated to implement and require precise eye-to-image alignment and are therefore impractical.
Other prior art systems utilize mechanically moving parts such as light shutters to create the stereoscopic video imaging and these systems are therefore complex to build, unreliable for long term use and uneconomical except for a few particular applications.